package wyx240407;

public class Day01 {
    double r;
    final double PI = Math.PI;

    public Day01() {
        this.r = 5;
    }

    public Day01(double r) {
        this.r = r;
    }

    public double getR() {
        return r;
    }

    public void setR(double r) {
        this.r = r;
    }

    public double getArea() {
        return PI * r * r;
    }

    public double getCircumference() {
        return 2 * PI * r;
    }
}
